Research on homomorphic encryption-based blockchain privacy and security focuses on enabling computations on encrypted data without exposing the underlying information, thereby enhancing confidentiality in decentralized networks. By integrating homomorphic encryption with blockchain, participants can perform secure transactions, verify computations, and execute smart contracts while keeping sensitive data hidden from other network nodes. This approach is particularly valuable in applications such as healthcare, finance, and IoT, where data privacy is paramount. Studies also investigate the trade-offs between computational overhead, scalability, and security guarantees, as well as hybrid models that combine homomorphic encryption with other cryptographic techniques like zero-knowledge proofs. Overall, homomorphic encryption strengthens blockchain systems by providing robust privacy protection while supporting verifiable and secure decentralized computations.